Men who want to lower their risk of a common cancer should masturbate and have sex more, according to research.
A new review of existing studies dating back 30 years found the more often men ejaculate, the less likely they are to develop prostate cancer.
Researchers recommended climaxing 21 times per month because the literature suggested it lowered the risk of disease by one-third.
Though the exact mechanism isn't well understood, the experts believe increased blood flow to the prostate could help flush carcinogens out of semen and other fluids.
A major review suggested that masturbating could lower the risk of prostate cancer, the most common form of the disease in American men
The findings come as the US sees an uptick in prostate cancers, including the recent deaths of OJ Simpson and Dexter Scott King, son of Martin Luther King Jr.
'The recommendation for routine ejaculation, particularly among specific age groups, presents an opportunity for proactive prostate health management,' the team wrote.
The review, published earlier this summer in the journal Clinical Genitourinary Cancer, looked at 11 studies featuring nearly 150,000 total participants. The studies were conducted between 1990 and 2023.
All included research examined the potential link between ejaculation and prostate cancer.
Some had as few as 40 participants, while others had thousands of volunteers. The men studied ranged from 20 to 80 years old.
Of the studies reviewed, one of the most promising came from Harvard Medical School.
The participants, from Harvard's Health Professionals Follow-Up Study, were mostly white health care professionals between ages 46 and 81.
The men were asked how many times they ejaculated per month during their 20s, 40s, and in the most recent year.
The team found that men who climaxed 21 or more times a month had a 31 percent lower risk of prostate cancer than those who did so just four to seven times a month.
The most recent study in the mix, published last year in The World Journal of Men's Health, focused on men ages 40 to 80 who were interviewed about their sex habits in their 20s, 30s, 40s, and the year prior.
The researchers found that men who ejaculated at least four times a month had the lowest prostate cancer risk compared to those who did so less often.
It's still unclear exactly how masturbation may lower the risk of prostate cancer, but experts believe it could be due to increased blood flow to the prostate, a walnut-sized organ that is only found in men.
Located between the base of the penis and the rectum, the prostate produces fluid that mixes with sperm to help it travel and survive.
The extra blood flow from masturbating could deliver vital oxygen and nutrients that help remove waste products linked to cancer. Additionally, ejaculating could help flush out harmful carcinogens that may build up in the semen.
A 2016 study from Boston University, included in the review, also suggested that frequent ejaculation stimulates changes in prostate tissues responsible for cells producing faster and creating more citrate, a compound shown to kill prostate cancer cells.
However, the earliest study, from 1990, showed no link between ejaculation, masturbation, contraceptive use, STDs, and prostate cancer.
OJ Simpson (left) died of prostate cancer in April, just two months after announcing his diagnosis. Dexter Scott King, son of Martin Luther King Jr, succumbed to the disease in January at age 62
There were several limitations to the review, mainly relying on self-reported data on ejaculation and other sexual behaviors.
'Despite these challenges, the clinical relevance of the findings cannot be overstated,' the researchers wrote.
'The emerging connection between ejaculation frequency and prostate health underscores the importance of incorporating sexual behavior into patient counselling and healthcare strategies.'
Prostate cancer is the most common form of the disease in men, affecting one in eight and killing 35,000, according to the American Cancer Society.
Men over 65 are the most likely to develop prostate cancer, making up as many as 60 percent of cases. The rate is even higher among black men, one of six of whom are expected to develop the disease.
Experts have attributed the rise to a growing population of older men, among whom the condition is most common.
Prostate cancer usually causes no symptoms in its beginning stages. When symptoms do develop, they often include issues urinating, loss of bladder and bowel control, painful ejaculation, and erectile dysfunction.